This invention relates to doors and to methods of construction thereof, and more particularly, to a form of wooden panel door and to a method of constructing the latter.
It has long been known in the prior art to employ a door as the means by which the closing and the opening of an entrance way is effected. More specifically, doors have long been used for this purpose irrespective of whether the entrance way to be equipped with a door is intended to function as a passageway through which entry is gained to the interior of a structure from the exterior thereof, or as a passageway through which various interior portions of the same structure are interconnected. The doors, which are employed in conjunction with the former type of entrance way, are normally referred to as exterior doors, whereas those, which are employed in conjunction with the latter type of entrance way, are referred to as interior doors.
In addition to the foregoing manner of classifying doors, i.e., as being either an exterior door or an interior door, there exists numerous other ways in which doors may be classified. For instance, doors may be classified according to the material of which they are constructed. In this regard, materials of a varied nature have long been employed in the construction of doors. One of these materials is wood.
Another way in which doors can be classified is according to intended function. Namely, there can be found in the prior art screen doors, which permit air flow therethrough and are thus particularly suited for employment during periods of warm weather; storm doors, which prevent air flow therethrough and are thus particularly suited for employment during periods of cold weather; combination doors, which can accommodate interchangeable panels whereby the doors may be made to function either in the manner of a screen door or in the manner of a storm door; etc.
Still another way of classifying doors is according to their architectural design. In recent years, it has become more and more common to find available on the market doors of sufficiently varying architectural styling that it is now virtually possible often times to select for employment in a given building a door that conforms in appearance, i.e., design to the architectural style of that particular building.
The availability of such a multiplicity of different styles of doors is attributable at least in part to the employment in the construction of these doors of panels of differing designs. Namely, in most of these instances the overall appearance of the door is established in large measure by the nature, i.e., the styling, of the individual panels, which have been utilized in the door. More specifically, from an economical standpoint, it is known to be measurably less expensive to effect the styling of a door through the appropriate selectivity of varied designs of individual door panels rather than to attempt to custom design each individual door to conform to the particular architectural styling of a given structure. This may explain, at least partially, the increased usage of panel doors that is known to have been occurring. By way of definition, the term "panel door" as used herein is intended to encompass all doors, but particularly those of wooden construction, which embody one or more individual members that are supportable in a frame structure which is formed by the stiles and the rails of the door.
Although many benefits are known to flow from the usage of panels in the construction of doors, there is also at least one notable unfavorable feature associated with the employment thereof in the manner referred to in the foregoing description. Reference is had here to the fact that such panels have been found to lack strength. Namely, from the standpoint of security, the panel represents the weakest portion of the door. Thus, where unauthorized entry is effected through breakage of the door, it is commonly been found that a rupture of the panel has occurred at the point where the panel is joined to its surround components, i.e., the stiles and/or rails of the door, etc. The reason for this is that in accordance with conventional practice, the side edges of the panel are normally machined so as to produce thereat a tenon, i.e., a portion of reduced thickness. Consequently, although the main segments of the panel may be capable of successfully withstanding the impact to which it is subjected in the course of an attempt at forcible entry through a typical door embodying such panels, the areas of the panel which have been machined to produce the aforementioned tenons frequently will break away because there is relatively little material left at these locations.
More and more concern has been evidenced at all levels of government, i.e., federal, state and local, concerning the matter of security and this is led to the adoption thereby of legislation and/or building codes specifying stricter requirements regarding the security aspects of the building components to be utilized particularly in residential structures. This in turn has led to the establishment of stricter security test criteria, which doors, including panel doors, desirably must pass in order to receive certain approvals relating to their potential usage in various types of building structures. In recognition of the existence of such security test criteria, efforts have been made towards providing a door capable of meeting such new security test criteria. However, notwithstanding such efforts on the part of the prior art, a need has still been shown to exist for a wooden panel door that would incorporate therein the best features of appearance or aesthetics as well as the best features of strength or security.
In the way of a brief summary, as more stringent building codes and legislation are adopted, the security aspects of existing residential building components are being increasingly assailed thereby. Namely, cognizance is being taken of the fact that wood doors constitute a major area through which forced entry into a building is achieved. Moreover, recognition is being given to the fact that the security effectiveness of such doors has been reduced over the years as a consequence of the manner in which materials are now being utilized in the construction of these doors and as a consequence of the implementation of certain cost saving steps relative thereto. Relative to this point, reference is had here by way of illustration to the now generally accepted practice employed in the industry of thinning up the cross-sections of the panels, which are being used in these doors.
It should now be readily apparent from the above that the additional requirements being imposed by the newly adopted building code legislation poses a serious problem insofar as concerns the capability of wood doors to comply therewith. This stems principally from both the nature of the material and typical manufacturing processes utilized in the construction thereof. For instance, typical door panels are being machined to approximately 1/4 inch thickness at the narrow end thereof, whereby little is being left to resist breakage at this location. Moreover, even when thicker panels made of solid wood are employed, they have proven in the past to be susceptible to both cracking and breaking. In an effort to improve the strength of present door panels, it has been known to make panels with crossband laminations. For the same purpose, doors have been produced embodying flat panels of 1/4 inch plywood. However, even though improvements in the strength of the door panels have been achieved through the usage of crossband laminations, and plywood panels, as well as some cost savings also in the case of the plywood panels, the surrounding components, i.e., the stiles and the rails of the door have continued to show failure in those areas where wood has been machined away for aesthetic reasons.
Thus, there has been established in the prior art a need for an improved panel door that embodies a construction which combines the best features of appearance and strength. In accordance with the present invention, there has been provided such a door. More specifically, a panel door has been provided, in which a notable improvement in the strength performance of the panels utilized therein has been achieved. Moreover, the nature of the panels being utilized therein presents a significantly better appearance in terms of both shadowline and aesthetics when compared to previously existing forms of door panels. In addition, the susceptibility of door panels to crack from natural stress, which is a trait that prior art forms of door panels are known to exhibit, has been reduced measurably in the case of the panels of the door of the present invention. Also, as regards another problem or shortcoming of prior art forms of panel design, i.e., the susceptibility of the panels embodied therein to undergo movement, this undesirable characteristic thereof has been significantly reduced in the case of the panels of the door of the present invention. This has been achieved as a consequence of the fact that the latter panels, as a characteristic thereof, embody more dimensional stability. Most importantly, however, the panel door of the present invention is advantageously characterized in the fact that it embodies a superior capability to successfully pass the security test criteria as established by the International Congress of Building Officials Building Code (I.C.B.O. Chapter 41). Heretofore, it has been demonstrated that a typical door of prior art construction will generally fail to pass the aforesaid security test criteria approximately 50 percent of the time as a result of the occurrence therein of either panel failure or surround component, i.e., stile and/or rail, failure.
It is therefore an object of the present invention to provide a new and improved door of wooden panel construction, and a method of construction thereof.
It is another object of the present invention to provide such a door, which is particularly suited for employment as an exterior door to effect the closing and the opening of an entrance way that functions as a passage between the exterior and the interior of a dwelling unit.
It is still another object of the present invention to provide such a door, which is advantageously characterized in the strength that it exhibits, as well as the fact that it combines the best features of appearance with those of strength.
A further object of the present invention is to provide such a door, which embodies panels that are of a particular construction.
A still further object of the present invention is to provide such a door embodying panels that are operative by virtue of their increased thickness to provide the door with an increase of 15% to 20% in the insulative value thereof as compared to the insulative value of panel doors of conventional construction.
Yet another object of the present invention is to provide such a door, the construction of which is effected through the employment of special joinery techniques.
Yet still another object of the present invention is to provide such a door, which is capable of satisfying the security test criteria set by official building codes, while concomitantly retaining the functionality and pleasing appearance associated with panel doors.